ruby, I don't think Andrew was at risk in quite the same way: though his life may have been in danger, he wouldn't have been targeted the same way because he wasn't fighting a land war against guerrilla forces as is the case in Iraq, which means his presence wouldn't have put his colleagues at special risk.
But I very much doubt that Harry could possibly have been sent to Iraq in secret. Wouldn't be more than a week or 2 before people started wondering where that redheaded kid in line to the throne was, how come UK bar takings seemed to be down etc, and then pretty soon the soldiers themselves would be gossiping. I don't think his whereabouts could have been kept quiet either, as it's no secret what regiment he's with. The minute word got into the papers, that would have been it.
But I think you're right: damned if he does, damned if he doesn't.